With the development of mobile communication technologies, the use of wired-based wireless technologies is being considered in order to construct broadband wireless access systems in the fields of broadband convergence networks (BcNs), mobile communications, and telematics.
Although research into various carrier frequencies and data modulation techniques has progressed to provide broadband wireless services, an access technique for directly utilizing conventional powerful wired networks has not yet developed.
Nowadays, much attention has been concentrated on standardization of new services due to a technical limit for making conventional wireless services more broadband. In particular, current wireless services provide a forward rate of 54 Mbps in the frequency band of 2.4 GHz (IEEE 802.11g) and are standardized such that IEEE 802.16m delivers speeds up to 1 Gbps. In addition, IEEE802.15.3c (Wireless Personal Network (WPAN)), ETSI/BRAN (Wireless LAN (WLAN)), ISO/TC 204 WG16 (Inter Vehicle Communication (IVC), Roadside Vehicle Communication (RVC)), and ECMA/ISO are standardized in the millimeter bands.
However, when constructing networks for various conventional wireless services, different wireless access systems are used in different frequency bands, thus increasing system construction and maintenance costs. Also, separate construction of the various wireless services is disadvantageous in terms of efficiency.
Therefore, the need for multiband separation and conversion techniques for supporting all multiband wireless communications with a single conversion device is increasing in order to cope with wireless services that are hereinafter developed.